Galleria mellonella

Galleria mellonella, the greater wax moth or honeycomb moth, is a moth of the family Pyralidae. G. mellonella is found throughout the world. It is one of two species of wax moths, with the other being the lesser wax moth. G. mellonella eggs are laid in the spring, and they have four life stages. Males are able to generate ultrasonic sound pulses, which, along with pheromones, are used in mating. The larvae of G. mellonella are also often used as a model organism in research. The greater wax moth is well known for its parasitization of honeybees and their hives. Because of the economic loss caused by this species, several control methods including heat treatment and chemical fumigants such as carbon dioxide have been used. G. mellonella was first reported as a pest in Asia, but then spread to northern Africa, Great Britain, some parts of Europe, northern America, and New Zealand. The species is now distributed throughout the globe. It has been reported in twenty-seven African countries, nine Asian countries, five North American countries, three Latin American countries, Australia, ten European countries, and five island countries. It is projected that the pest may spread further, especially due to climate change. G. mellonella can be found where honeybees are cultivated. G. mellonella larvae parasitize the honeybee. Eggs are laid in the cracks and crevices inside the hive, which minimizes egg detection. Once eggs hatch, they feed on the midrib of the wax comb, the cast skins of bee larvae, pollen, and small quantities of propolis and honey. Live larvae are never eaten. Shortly after emergence, G. mellonella females lay their eggs in the small cracks and crevices inside a beehive. Females prefer to lay their eggs in strong, healthy bee colonies over weaker colonies, but weaker colonies have a higher rate of G. mellonella infestation. Eggs are laid in clusters of varying number depending on the region. Clusters of 50-150 eggs have been reported in the United States, whereas clusters of 300-600 eggs have commonly been reported in India. Up to 1800 eggs have been deposited by a single female. The life cycle of G. mellonella proceeds through four stages: egg, larvae, pupae and adult. Generally, eggs are laid in the early spring and the moth undergoes four to six generations annually. By December, the eggs, larvae, and pupae enter diapause in wait for warmer weather. The effects of temperature and humidity on life stages have been most thoroughly studied. Temperatures around 29–33 °C (84–91 °F) and humidity levels around 29-33% are optimal for development, though studies in Kansas have shown normal larval development at temperatures as high as 37 °C (99 °F). Average temperatures higher than 45 °C (113 °F) have been shown to be lethal for larva. Lower temperatures at 23 °C (73 °F), however, resulted in only part of the life cycle being completed. At temperatures below 0 °C (32 °F), even short exposures kill larva and adults.